Binge-Eating Disorder: Prevalence, Predictors, and Management in the Primary Care Setting

• What are the clinical features of BED?

BED and Obesity

The specific impact of BED on health is difficult to separate from the impact of obesity on health, as the two conditions frequently co-occur and are confounded in many studies. Of relevance to the primary care setting, many BED patients report gaining a substantial amount of weight in the year prior to seeking treatment [57].

Although individuals with BED are often obese, proponents of classifying BED as a separate DSM diagnosis argue that individuals with BED differ from their non-BED obese counterparts in regards to eating patterns, eating disordered psychopathology, and associated features and comorbidities. Individuals with BED consume more calories in laboratory studies than weight-matched controls [6,7,58]. In contrast, studies utilizing ecological momentary assessment (ie, real-time assessments) found no differences between BED obese and non-BED obese participants in the frequency of self-reported binge eating and caloric intake during binge eating episodes [59,60]. BED participants, however, were more likely to report higher stress, desire to binge, negative affect, dietary restraint, and being alone immediately before self-reported binge eating episodes. Furthermore, individuals with BED also demonstrate more ED-related psychopathology than non-BED obese individuals [61–63]. Psychiatric comorbidity is also higher among BED obese individuals as compared their non-BED obese counterparts, and the increased comorbidity is accounted for by the severity of binge eating as opposed to the severity of obesity [6,64–67]. In addition, research demonstrates that obese individuals with BED, as compared with non-obese BED patients, have a poorer quality of life [68].

BED and Bulimia Nervosa

Numerous studies have supported the distinction between bulimia nervosa and BED [69–76]. Diagnostically, bulimia nervosa differs from BED by its requirement of recurrent inappropriate compensatory behaviors in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; or excessive exercise [3]. BED and bulimia nervosa are distinguished by distinct risk factors, prevalence, course, and treatment outcomes [28,67,77]. Individuals with BED are less likely than individuals with bulimia to diet before onset of the disorder, and fewer individuals with BED cross over into other ED diagnostic categories [26,78–81]. Finally, BED and bulimia nervosa are associated with different constellations of ED-related symptoms and associated features [28,63,79]. For example, relative to BE patients, those with bulimia show greater work impairment and psychiatric comorbidity [28], higher dietary restraint and eating concerns [63], and lower rates of obesity [79].

Psychiatric Comorbidity

BED is associated with poor social adjustment, greater functional impairment, and significant psychiatric comorbidity, including overall distress and suicidality [67]. In a study of comorbidity with only selected disorders (mood, anxiety, impulse-control, and substance use disorder), 78.9% of individuals with BED had a lifetime history of at least one comorbidity, 20.2% had one comorbid disorder, 9.8% had two, and 48.9% had three or more [28]. Furthermore, the presence of current psychiatric comorbidity is associated with greater ED-related psychopathology and associated distress [40,41]. The most common comorbidities (lifetime rates) are specific phobia (37.1%), social phobia (31.9%), major depressive disorder (32.3%), post-traumatic stress disorder (PTSD) (26.3%), alcohol abuse/dependence (21.4%), conduct disorder (20%), attention-deficit/ hyperactivity disorder (19.8%), illicit drug use/dependence (19.4%), and oppositional-defiant disorder (18%) [28]. A recent report supports that this level of comorbidity is evident in primary care settings, noting that PTSD in particular is common and associated with a host of other difficulties, including depression, anxiety, drug use disorders, greater eating disorder pathology, and poorer psychological functioning [82]. Personality disorders are also commonly comorbid with BED, with the highest lifetime rates for avoidant (11%), obsessive compulsive (10%), and borderline (9%) personality disorders [83]. Finally, cigarette smoking is also associated with binge eating [83,84], likely evolving out of a weight-control smoking profile [85], and this is of relevance to the primary care setting in that smokers with BED gain more weight upon smoking cessation than do their non-BED counterparts [86].